MEDICAL BIOLOGY, HUMAN ANATOMY, PHYSIOLOGY AND PATHOLOGY - Y.I. Fedoniuk 2010

ANATOMY, PHYSIOLOGY, PATHOLOGY

SECTION 4. THE BLOOD SYSTEM

BLOOD GAS TRANSPORT

1. CHARACTERISTICS OF ERYTHROCYTES

Human erythrocytes are round, biconcave, enucleated "Cells" with a diameter of about 7.5 µm. The membrane of these cells is quite elastic, allowing the erythrocyte to easily change its shape and pass through the smallest capillaries where gas exchange takes place. The Cytoplasm of erythrocytes contains Hemoglobin, which amounts to 36-37 pg in men and 32-33 pg in women, enabling erythrocytes to transport O2 and CO2. This transport occurs only when hemoglobin is contained within The Cell. Upon hemolysis, when hemoglobin is released into the Blood Plasma, this function is lost.

In addition to gases, erythrocytes transport BIOLOGICALLY ACTIVE SUBSTANCES. The latter bind to receptors located on The erythrocyte membrane.

Erythrocytes are produced in the Cytology/practical/86.html">Red Bone Marrow and circulate in the blood, performing their Functions for 120 days, after which they are destroyed in the Cells of the reticuloendothelial system (Liver, Spleen).

Normally, the blood of a healthy man contains (4.5-5.0) · 1012/L, and in women - (4.0-4.5) · 1012/L of erythrocytes.

An increase in erythrocyte concentration above normal is called erythrocytosis, while a decrease is termed erythropenia. These fluctuations are observed in various diseases. However, erythrocytosis can also occur under certain physiological conditions: during intense muscular exertion or when a person is at high altitudes. This process is explained by the body's adaptation to oxygen deprivation.



Last update: 08/08/2026

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